When I was on a 48-hour holter monitor for my heart, I occasionally noticed a tingling electric-like sensation emanating from one of the electrodes into the skin under it. The little zaps pulsed for about 1 minute and then faded away. Both times it was the same electrode in the same location.
It was not a feeling of itching or skin irritation like an allergic reaction, but a distinct sensation of tingling like low-level electricity. It was very distinct from the deeper chest pains I have been recording in my heart monitor log.
My husband (who is an expert in electronics) suggested that even a little moisture, possibly secreted by sweat, or by the skin having an allergic reaction to contact with the electrode, might have caused this.
After the electrodes were taken off, the most reddened skin appeared under the electrode that tingled the most.
I can’t find anything about this online through random Google searches and I don’t have time to research it further right now. I wonder if anyone else has experienced this.